In U.S. Patent Application Publication No. US 2003/0039730 A1, a process line for preparing and filling bags having one mesh wall with produce or the like is disclosed. In that process, rolls of plastic sheeting and mesh are advanced as a strip, sealed together, filled with product, and then closed.
A particular heat sealing die is disclosed, for forming a pair of heat seal lines, and for simultaneously cutting the sealed plastic sheeting and mesh strip between the two heat seal lines. This die exhibits significant commercial advantage of use in a high volume process of heat sealing of plastic and mesh sheets, or, if desired, mesh sheets with mesh sheets or plastic sheets with plastic sheets. Additionally, a heated cutter edge is shown, positioned between the two heat seal bars or arms.
By this invention, an improvement is provided, in which a heat seal die which forms one or more heat seal lines in plastic sheeting or mesh may have the benefit of easily adjustable spacing of the heat seal bars or arms, (and a heated cutter if present) and respective anvil blocks or backing plates used for such sealing and cutting operations, so that such spacing during sealing and/or cutting operations can be adjustably and independently controlled, to achieve optimum sealing and cutting conditions for the plastic sheet/mesh bags that are being formed. Because of the ease of adjustability, less down time in the manufacturing process may be realized, for greater manufacturing efficiency.